The TOWIE star took part in a charity special of the survival show, to air later this year, alongside celebs including Made In Chelsea's Ollie Locke and JLS' Aston Merrygold.
Speaking to ITV's Lorraine, Lydia said: "I filmed for Bear Grylls' Island earlier this year and it's airing towards the end of the summer.
"It was tough but I think it will be absolutely brilliant for you guys to watch because we go through a rollercoaster of emotions. It was an incredible lifetime experience."
Lydia added: "I thought I was this weak little girl from Essex who couldn't really lift much, so I proved myself wrong."
Celebrity The Island with Bear Grylls is part of a Stand Up 2 Cancer campaign. Ten celebrities lived on the island for two weeks, fending for themselves.